Historians say the Tannenbaum dates to the Druids of northern Europe, who lived several centuries before Christ and used pine boughs to mark the winter solstice. Even some evangelical Christians, acknowledging its pagan past, jokingly refer to their trees as ''Babylon bushes.''

But because of the central role the Christmas tree plays in modern celebrations, others insist it's a de facto religious symbol that has no place in schools or other public buildings.

Humbug, says David Robson, a U.S. horticulturist who has researched the tree's storied past and contends the only thing remotely religious about it is the star or angel perched on top.

''It's not a Christian symbol per se,'' said Robson, who works with the University of Illinois' extension service in Springfield. ''It hasn't done anything wrong. It doesn't have the ability to do anything except bring some joy and keep the soil from eroding before it's cut down.''

In France, the ''sapin de Noel'' beloved by millions has become the focus of a lively debate.

A dozen students at a high school east of Paris, convinced that a Christmas tree their principal put up in the entry hall violates a law banning conspicuous religious symbols in public schools, have pressured administrators to remove it.

The controversy, which one commentator wryly dubbed ''the pine polemic,'' has caused a stir in proudly secular France.

''A cr che is a religious symbol. Not a tree,'' Patrick Gonthier, who heads a French teachers' union, told RTL radio.

In Florida, a furor over whether Christmas trees are religious symbols ended last week when officials reversed a decision to restrict their display in public buildings.

U.S. courts have ruled that Christmas trees are secular symbols, although some have decreed that putting them up in public places gives other groups the right to add a holiday symbol as well.

The tree challenges come amid a sharp decline in the religious character of Christmas in some places. In Austria, only 7 percent of respondents to a Dec. 12 survey by the OGM polling institute cited faith as the chief factor in their Christmas celebrations.

''Christmas is increasingly losing its religious focus,'' pollster Peter Hajek said.

Officials at Indiana University's School of Law, responding to complaints about the religious implications of a campus tree, replaced it with two smaller trees and a sleigh filled with poinsettias.